Carburetor



May 5, 1936. H. B. NoRRls CARBURETOR Filed March 2l, 1931 2 Sheets-Sheet l l LQ I :Owl y i* [rw C y I :o l: E "E L, #my MW M55-LGR H. B. NORRIS May 5, 1936.

CARBURETOR 2 Sheets-Sheet 2 Filed March 2l, 1951 INVENTOR- nfl/Cw am e@ AT ORNEV Patented May 5, 1936 MNHTED STATES PATENT OFFICE CARBURETOR Application March 21,

13 Claims.

My invention relates to new and useful improvements in carburetors, and more particularly to carburetors such as are employed to provide a combustible mixture of fuel and air to an internal combustion engine. The temperature of the engine determines the richness of the mixture, i. e., the ratio of fuel to air, which is necessary for engine operation, the lower the temperature, the more rich the mixture must be in fuel. It is therefore an object of my invention to provide a carburetor having means to regulate the quality of the combustible mixture supplied thereby.

Another object is to provide means operable at will to vary the quality of the discharge from the main air and fuel inlets without affecting the normal setting of the carburetor.

Another object is to provide a carburetor which will supply a mixture of the desired quality for proper engine operation in cold weather.

The invention consists in the improved construction and combination of parts, to be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specification, I have fully and clearly illustrated a preferred embodiment of my invention, in which drawings- Figure 1 is a view in elevation of a carburetor embodying my invention;

Fig. 2 is a top plan view thereof, partly in section on the line 2 2 of Fig. 1;

Fig. 3 is a detail sectional view on line 3--3 of Fig. 2;

Fig. 4 is a detail of an operating element, and

Fig. 5 is a View in vertical central section on the line 5 5 of Fig. 2.

Referring to the drawings by characters of 4.0 reference, I designates generally a carburetor body or casing member having a mixing chamber 2 with main air and fuel inlets 3, 4, respectively, opening thereinto, and with a mixture outlet 5 opening therefrom. In the outlet 5 is a throttle valve 5a, preferably of the butterfly type, mounted on a shaft 5b journaled inv and projecting through the side walls of the casing. The fuel inlet 4 is preferably concentric with the bore 50 of the mixing chamber, and comprises a fuel nozzle 6 which is reciprocably supported in a tubular element 1 projecting from the bottom wall of the air inlet toward the mixing chamber. 'I'he lower end of nozzle 6 within element I has an annular flange 8 forming a piston and co- 1931, Serial No. 524,250

operating with the bore of element 'I to form a dash-pot resisting means. Within the dash-pot and seated on the flange 8 is a coil spring 9 which aids in resisting movement of the nozzle t upward or toward chamber 2. Cooperating with the bore of nozzle 6 is a valve means I0 normally fixed relative to the casing I and preferably of the metering pin type, the stem of which extends downward through suitable packing means iE and the bottom wall of the air inlet to provide for regulation of the metering pin external of the carburetor, as at I2. The nozzle 6 is fed from a constant level fuel chamber or float controlled reservoir I3 which opens into the element 'l below piston S. Air flow to the mixing chamber is controlled by automatically acting suction operated valve means I4 responsive to the degree of sub-atmospheric pressure in the mixing chamber, and which normally restricts air flow to said chamber. The means Ill preferably comprises upwardly inclined converging vane members or iiap valves which are swingingly supported at their lower edges by substantially parallel pintles or shafts I5 carried by the walls of the air inlet. The vanes have an aperture I6 therethrough which receives the upper end of the fuel nozzle such that the nozzle discharges adjacent the free edges of the vanes, the aperture being of sufficient diameter to provide an annular primary air inlet around the nozzle to the mixing chamber when the vanes are closed. The vanes and nozzle are interconnected by arm or finger members I'I rigid with the vanes and which extend into a circumferential recess I8 in the nozzle, so that movement of the vanes in response to engine suction will move the nozzle relative to the metering pin and thereby regulate or control the inlet area to the nozzle around the metering pin I0.

Through the side wall of the mixing chamber above the oat chamber is an aperture I9 which is above and substantially in the vertical plane of the pintles I5, and which has its bore substantially parallel thereto. Secured and sealed, as by threaded engagement in the aperture I9, is a bushing or the like having a longitudinal bore 2| serving as a bearing, and in which is journaled a shaft member 22 preferably substantially fitting the bore 2| to prevent ingress of air to the mixing chamber around member 22. The shaft member 22 has, within the mixing chamber, a depending arm 23 which normally lies substantially against the mixing chamber wall, see Fig. 3, but which is movable upon rotation of shaft 22, into direct engagement with the inclined upper surface of one of the vane members I4, as shown by the dotted lines, Fig. 3. The outer end of shaft 22 has an operating arm 24, preferably depending therefrom, and which terminates in an eye or loop 25. The casing I carries an operating arm or lever 26 which is journaled for rotation, preferably on a vertical axis, and which cooperates with a stop 26a to limit counterclockwise rotation. Clockwise rotation of arm 26 is limited by a lug 26b carried thereby, and also cooperating with stop 26a. On the lever 26 is an apertured lug or the like 21, and extending between the lever 26 and arm 24 is a yieldable connecting means 28, preferably a resilient coil spring having its ends respectively secured to and in the apertures of lug 21 and loop 25. The spring 28 is normally in a neutral state, or inert, and exerting neither tension nor compression, but is operable upon counterclockwise rotation of lever 26 to be placed under tension thereby to exert its force through and to rotate or swing arm 23 into engagement with the means I4 to load the same and exert an increased resistance to opening movement thereof by engine suction. It will be noted that the greater the amount of counter-clockwise movement of lever 26 from the position of Fig. 2, the greater will be the tension of spring 28, and consequently the greater will be the load placed upon means I4.

The lever 26 is preferably carried rigidly by a substantially vertical housing member 29 which is rotatable in the bore of a casing member 36, which is rigidly carried by the casing I. The housing member 29 extends downward through the cover of the float chamber and has a central conduit member 3I which opens at its lower end below the normal liquid level in the float chamber, and which opens at its upper end into a fluid chamber 32 in the housing member, the bottom wall of chamber 32 being defined by a horizontal partition or the like 33 centrally apertured for the member 3 I. Opening into and from the bore of casing member 30 are a plurality of passages, namely, an air inlet port or passage 34 from atmosphere a primer passage 35 which discharges, as at 36, into the outlet 5 beyond the throttle valve 5B, and a discharge passage 31 which opens through a nozzle 38 into the mixing chamber anterior to the throttle valve. In the housing member 29 are a plurality of ports 39, 40 and 4I, 42, cooperating respectively with passages 34, 31 and 35, and so arranged that when port 39 registers with passage 34 the port 40 is in registry with passage 31, and port 42 is out of registry with passage 35; that when port 4I is in registry with passage 31, ports 39 and 42 are out 0f registry with passages 34 and 35, and that when port 42 is in registry with passage 35 the ports 39 and 40, 4I are out of registry with passages 34 and 31, respectively. 'I'hat one of the vane members I4 which cooperates with arm 23 is preferably recessed at its upper free edge, as at 43, to provide clearance for said arm 23 when the vane member is wide open, and in substantially vertical position.

It may be noted that the carburetor is provided with means to move the throttle toward open position upon operation of the lever 26. 'I'his means preferably comprises a cam face 44 on the housing member 29, which cooperates with a. cam follower or pin 45 carried by a lever 46 rigid with the throttle shaft 5b, so that preferably prior to registration of port 4I and passage 31 the throttle will be moved, which opening movement will be increased as the lever 26 is continued in its counterclockwise swing.

The operation of my device is as follows: The carburetor having been operatively connected to an internal combustion engine and a source of fuel supply, the lever 26 is rotated counterclockwise until it engages the stop 26EL which serves through the cam face 44 and pin 45 to crack open the throttle and simultaneously therewith to place port 42 in registry with primer passage 35 and also to tension spring 28, thus putting a greatly increased load or resistance on the vanes I4. If the engine is now turned over, the vanes will be held closed, both by the spring 28 and the spring 9, which latter spring preferably acts to maintain the vanes closed for engine speeds up to and slightly above idle speed, i. e., about 300 R. P. M., so that air will be supplied to the mixing chamber only through the annular space around the nozzle 6. The suction of the engine will act to draw fuel from the fuel passage 35, and some fuel and air from the main nozzle 6 and the annular space therearound, the solid liquid fuel which discharges from the port 36 being supplied by direct communication with the fuel in the oat chamber. In normal operation, as soon as the engine starts, the lever 26 is returned toward normal running position (Fig. 2), so as to bring port 4I into registry with nozzle 38, which may be termed warmingup position. In this position the nozzle 38 will supplement the fuel discharged from the main nozzle and the spring 28 will remain under tension and continue, but to a lesser degree, to resist with spring 9 the opening movement of the vanes I4. Due to the increased load exerted by spring 28 supplemental to the load of spring 9 and acting on the vanes in this position of lever 26, the ratio of air to fuel for a given suction or sub-atmospheric pressure in the mixing chamber will be decreased, i. e., a richer mixture will be provided by the main air and fuel inlets than when the lever 26 is in normal running position, Fig. 2. With the lever 26 in normal running position, Fig. 2, the vanes I4 will start to open at a vacuum, in the neighborhood of three to four inches of water, whereas, with the vanes I4 loaded by the spring 28 when lever 26 is in warming-up position, the vanes will not start toopen until there is a vacuum in the mixing chamber of about twelve inches of water, and when the lever 26 is moved completely to priming or starting position, there will be a vacuum of upward of thirty inches of water in the mixing chamber in order to start opening movement of the vanes I4. The foregoing vacuums are stated solely as illustrative of the ability of my device to regulate or control the mixing chamber vacuums or sub-atmospheric pressures, and to indicate substantially the sub-atmospheric pressures which are required to cause initial opening movement of the vanes. It is to be noted that the increased Vacuums in the mixing chamber, depending on the position of lever 26, which are required to cause opening of the vanes, will result, assuming the ports 4I and 42 to be of substantially equal area, in an increased discharge of fuel per unit of time from the nozzle 38 and a further increased rate from the passage 35. However, in practice, these ports 4I, 42 may have a ratio of areas of substantially I to 2, so that it may be seen that the supply to the engine when the discharge is through port 36. is extremely rich in fuel. The separate discharges from nozzle 38, .or from-passage 3,5., which are at increased rat-es under these conditions, will serve to further enrich the already increased ratio of fuel to air from the main :inlets 3, 4Il, thereby providing the desired rich mixtures for cold weather engine operation.

'Ihe carburetor generally shown and described herein is the invention of Walter H. Weber, the subject matter of which is disclosed andclaimed in an application filed by him on December 31, 1929 for Carburetors, Serial No. 417,609, which matured to Patent No. 1,981,483 granted Nov. 20, 1934. I

What I claim Aand desire to secure by 'Letters Patent of the United States is:

1. A carburetor comprising a casing having a mixing chamber with regulatable main air and fuel inlets opening thereinto and with a mixture .outlet opening therefrom, valve means controlling the flow from said air inlet to said chamber, valve means for said fuel inlet, means operatively connecting said second-named valve means to said first-named valve means for regulation thereby, said fuel inlet discharging into said mixing chamber on the outlet side of said air inlet controlling means, and normally ineffective means independent of said connecting means and operable for direct engagement with said first-named valve means to resist operation thereof thereby to increase the ratio of fuel to air supplied to said chamber.

2. A carburetor comprising a casing having a mixing chamber with main air and fuel inlets thereto and a mixture outlet therefrom, means to supplement the fuel discharged from said main fuel inlet, means responsive to mixing chamber suction and operable automatically to control the ratio of air to fuel supplied by said main inlets, and means operable to control said supplemental means and simultaneously to regulate said responsive means whereby to vary the normal ratio of air to fuel supplied to said mixing chamber from said main inlets.

3. A carburetor comprising a casing having a mixing chamber with main air and fuel inlets thereto and a mixture outlet therefrom, a fuel supply conduit for supplementing the discharge from said main fuel inlet, normally closed valve means to control said conduit, suction operative means to control the ratio of fuel to air supplied to said chamber from said main inlets, and means operable to open said valve means and simultaneously to increase the ratio of fuel to air supplied from said main inlets.

4. A carburetor comprising a casing having a mixing chamber with main air and fuel inlets thereto and a mixture outlet therefrom, a throttle valve intermediate said chamber and said outlet, a fuel supply conduit opening into said outlet, a fuel supply conduit opening into said chamber, valve means controlling said conduits, a metering valve for said fuel inlet, air valve means in said air inlet operatively connected to said metering valve to control the ratio of fuel to air supplied from said main inlets, means resisting said air valve means, and yieldable resisting means operable on said air valve means upon operation of said first-named valve means, said last-named means exerting an increased resistance to operation of said air valve means when said first-named valve means is moved to open said second-named conduit whereby to increase the ratio of fuel to air supplied from said main inlets.

5. A carburetor comprising a casing having a mixing chamber with main lair land fuel inlets thereto and a mixture outlet therefrom, a throt- Y tle valve vintermediate said chamber and said outlet, a fuel supply conduit opening into said outlet, a fuel supply conduit opening into said .chambenvalve means controlling said conduits, a

operable on said air valve means upon operation of said first-named valve means, said last-named means exerting an increased resistance to operation of said air valve means when said rstnamed Valve means is moved to open said second-named conduit whereby to increase the ratio of fuel to air supplied from said main inlets, and said last-named means exerting a predetermined greater increase of resistance to operation of said air valve means when said first-named valve means is moved to open said first-named conduit.

6. A carburetor comprising a casing having a mixing chamber with an air inlet thereto, a suction-operated swingingly supported vane member normally lrestricting the passage of air from said inlet to said chamber, a movable fuel nozzle discharging into said chamber adjacent the free edge of said vane member, a fuel valve cooperable with said nozzle and normally Vxed relative to said casing, means interconnecting said Vane member and said nozzle whereby said vane member controls the discharge from said nozzle, and manually operable loading means movable into direct engagement with said Vane member to resist operation of said vane member by mixing chamber suction,

7. A carburetor comprising a casing having a mixing chamber with an air inlet thereto, cooperable suction-operated vane members positioned in said inlet and journaled adjacent the side Walls thereof for swinging movement to open position, said vane members having an aperture therethrough, a movable fuel nozzle concentric with said aperture and discharging therethrough into said chamber, a fuel valve cooperable with said nozzle and normally xed relative to said casing, means interconnecting one of said vane members and said nozzle whereby said one vanelv member controls the discharge from said nozzle, an arm member journaled in a wall of Said casing and having a part operable to engage one of said vane members, means to move said arm member into engagement With said one Vane member, and yielding means interconnecting said last-named means and said arm member whereby the resistance to operation of said one vane member may be controlled.

8. A carburetor comprising a casing having a mixing chamber with an air inlet thereto, a suction-operated valve normally restricting the pasto resist operation thereof by mixing chamber suction.

9. A carburetor comprising a casing having a passageway therethrough, main air and fuel inlets opening into said passageway, a throttle valve controlling the outlet from said passageway, suction operative valve means controlling said main air inlet, supplemental fuel supply means for said passageway, a, valve controlling said supplemental fuel supply means, loading means movable into the path of movement of said suction operative valve means to resist opening movement thereof, means to operate said supplemental fuel supply valve, and resilient means operatively connecting said supplemental fuel supply valve and said loading means whereby operation of said supplemental fuel supply valve will actuate said loading means.

10. A carburetor comprising a casing having a passageway therethrough, main air and fuel 4 inlets opening into said passageway, a throttle valve controlling the outlet from said passageway, suction operative valve means controlling said main air inlet, supplemental fuel supply means for said passageway, a valve controlling said supplemental fuel supply means, an arm member movable into the path of movement of said suction operative valve means to resist opening movement thereof, means external of said casing to operate said supplemental fuel supply valve, said arm member having a portion projecting through said casing, and resilient means operatively connecting said supplemental fuel supply valve and said arm member portion whereby operation of said supplemental fuel supply valve will actuate said arm member.

11. A carburetor comprising a casing having a passageway therethrough, main air and fuel inlets opening into said passageway, a throttle valve controlling the outlet from said passageway, suction operative valve means controlling said main air inlet, a supplemental fuel supply conduit discharging into said passageway, a valve having a port therein positioned in and registerable with said conduit, loading means movable into the path of movement of said suction operative valve means to resist opening movement thereof, means to operate said second-named valve, and resilient means operatively connecting said second-named valve and said loading means whereby operation of said second-named valve will actuate said loading means.

12. A carburetor comprising a casing having a mixing chamber with main air and fuel inlets opening thereinto and with a mixture outlet opening therefrom, a throttle valve controlling said outlet, a valve controlling said fuel inlet, suction operative valve means controlling flow from said air inlet to said chamber, said fuel inlet discharging into said chamber on the outlet side of said valve means. means interconnecting said valve and said valve means whereby said valve means automatically controls said valve thereby to establish a predetermined ratio of fuel to air at a given sub-atmospheric pressure in said mixing chamber, means resisting operation of said valve means, normally ineffective means independent of said interconnecting means and said throttle valve and cooperable with said valve means to resist operation thereof, and means to move said last-named means into cooperable relation to said -valve means.

13. A carburetor comprising a casing' having a mixing chamber with main air and fuel inlets HARRY BARKER NORRIS. 

